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How to roast a leg of lamb
Follow our basic recipe and cooking tips, and see what celebrity chefs Jamie
Oliver, Nigella Lawson and Mary Berry recommend
Whether it’s a Sunday roast, a Friday night dinner party or a mid-week slow cook, a roast leg of lamb is a delicious and versatile joint of meat that will wow your dinner guests with minimal effort.
Our guide covers everything from how long to cook the meat, what size leg to buy and how much lamb you’ll need per person. Plus, the herbs and spices that will enhance its flavour, making sure the lamb is the star of the show.
Take the lamb out of the fridge for at least an hour before cooking so it can get to room temperature.
Set the oven to 220°C/200°C fan/Gas 7
Weigh the meat to calculate the cooking time – it’s approximately 20 minutes per 450g/lb, plus an extra 20 minutes if you like it medium.
Drizzle with olive oil and rub all over, before seasoning generously with salt and pepper.
Place the lamb into a roasting pan and put into the preheated oven.
Cook for 20 minutes before turning the oven down to 190°C/170°C fan/Gas 5 and continuing to cook until it’s done.
Take it out of the oven, loosely cover with foil and let it rest for around 15 to 20 minutes before carving and serving.
Leg of lamb cooking times
Once you know the weight of the meat, you can work out roughly how long it will take to cook it. The total cooking times for a leg of lamb (medium) are as follows:
750g 1 hour 5 minutes
1kg 1 hour 15 minutes
1.5kg 1 hour 40 minutes
2kg 2 hours 5 minutes
2.25kg 2 hours 30 minutes
2.50kg 2 hours 50 minutes
2.75kg 3 hours
If you prefer it well done, you can alter the cooking times to 30 minutes per 450g/lb, plus an extra 30 minutes.
Make sure you also check the cooking times listed on the packaging, or ask the butcher if you’re not buying from a supermarket.
Cooking times can also vary depending on how well your oven sticks to its temperature. In our tests, we've found some that overheat by 30ºC more than the temperature you set, which is enough to turn a perfectly tender joint into a crispy mess.
If you’re trying to calculate how much you’ll need to cook, a good rule of thumb is 400g + 200g per person. The list below will give you an idea of roughly what weight you'll need to feed everyone at your dinner table.
Aldi, Asda, Morrisons, Sainsbury's and Tesco are some of the most searched-for supermarkets that stock lamb legs. However, lamb is widely available from nearly every supermarket or butchers in the UK and Ireland. If you're not sure where to go, see our round-up of the best and worst supermarkets. We also reveal the cheapest supermarket every month.
Aldi has whole and half legs of fresh lamb, starting from £10.99 per kilogram for a half leg, and £11.99 per kilogram for a whole leg. It doesn't offer home delivery, but you can click and collect groceries from selected stores for £4.99.
Asda sells only whole legs of its own-brand lamb, costing from £9/kg. It offers home delivery, with a same-day express option for £8.50. Otherwise, you can click and collect from most stores for £3.50.
Morrisons offers a selection of fresh whole lamb legs starting from £11/kg, or a frozen half leg for £14.10/kg. Morrisons can deliver groceries for anywhere from £1.50 to £6 depending on where you live, what time you book your one-hour delivery slot and how much your order costs. You can also click and collect for free on orders of £25 and more.
Sainsbury's stocks a wide range of own-brand options costing from £13/kg for a whole leg and £14/kg for a half leg. You can get home delivery from £2 for orders of more than £40 or you can click and collect from £2 for orders of £25 or more. In some cities, you can even order your groceries from delivery apps – although, unfortunately, you can't earn any Nectar points and delivery is much more expensive this way.
Tesco has its own-brand options starting from £14/kg for a half leg and £13/kg for a whole leg. It offers click and collect slots from £2, otherwise you can order groceries directly to your door from £2 to £7 for a one-hour delivery slot.
While a well-cooked leg of lamb will taste fantastic on its own, fresh herbs and the right accompaniments can add a delicious depth of flavour.
Here are some of the best herbs, spices, sauces, and condiments to pair with lamb:
Rosemary The classic combination. Stud the sprigs into the meat before cooking or add to a marinade or butter.
Garlic Slather in a garlic butter or stud garlic cloves into the meat before cooking.
Black pepper Create a mustard and black pepper crust, pair with a black pepper sauce or simply season with black pepper before roasting.
Cumin Cover your lamb with cumin (ground or seeds) before cooking to create a crust.
Curry powder or Baharat can be used as a dry rub or mixed into stews or other wet dishes.
Oregano Mix with olive oil, garlic, salt, and pepper and rubbed over the meat before roasting.
Thyme Simply add the stalks and all to the pan when cooking.
Mint and mint sauce Pair roast lamb with a mint sauce or jelly, sprinkle fresh mint leaves into a side salad or make a mint marinade.
Mustard Rub English or wholegrain mustard into the lamb before roasting to leave a spicy crust.
Yoghurt/tzatziki Serve on the side, in a gyro or drizzled over sliced lamb.
Curry Lamb goes perfectly in a curry, particularly a rogan josh, jalfrezi or bhuna.
GravyUse the juices from the cooked lamb to make a homemade gravy.
Chimichurri Made of finely chopped parsley, minced garlic, olive oil, oregano and red wine vinegar, fresh and vibrant chimichurri sauce can be served alongside lamb or used as a marinade before cooking.
Tomato relish Serve as a condiment with any lamb dish.
Gremolata Garnish with this tangy green sauce made up of chopped parsley, lemon zest and garlic.
Aioli – a creamy, garlic sauce that will taste best served with lamb and potatoes.
Best red wines: serve your lamb with one of our top-rated picks for a perfect pairing
How to slow roast a leg of lamb
To slow roast, all you need to do is lower the heat and lengthen the cooking time. We also advise covering the lamb with foil to help the meat retain its moisture.
Take the lamb out of the fridge for at least an hour before cooking so it can get to room temperature.
Set the oven to 170°C/140°C fan/Gas 3
Weigh your lamb to calculate the correct cooking time – add around three hours to the cooking times listed above. For example, five to six hours for 2kg.
Drizzle with olive oil and rub all over, before seasoning generously with salt and pepper.
Place the lamb into a roasting pan, cover loosely with foil and put into the preheated oven.
Remove the foil 45 minutes before it’s done so the meat can brown.
When the meat is cooked to your preference, take it out of the oven, loosely cover it with foil and let it rest for 15 to 20 minutes before carving and serving.
Coined the best roast leg of lamb recipe, Jamie uses a marinade made up of rosemary, garlic, olive oil and lemon zest to flavour the lamb and advises cooking the joint on the hot bars in the oven rather than in a roasting pan.
Another one of Jamie’s leg of lamb recipes swaps out the marinade for a herby butter and the hot bars for a traditional pan, filled with veg.
Nigella Lawson's roast leg of lamb recipes
Like Jamie, Nigella also rubs a leg of lamb with a marinade. But this one uses rosemary, oregano, lemon, orange, garlic, olive oil and salt, which once cooked will form a soft, fresh crust on the top of the joint.
